Objective To investigate the impact of desmoglein 3 （Dsg3） on the proliferation of peripheral T lymphocytes from patients with pemphigus vulgaris （PV）. Methods Peripheral blood mononuclear cells （PBMCs） were obtained from 12 patients with PV and 22 normal human controls, cultured with or without the presence of Dsg3 or phytohemagglutinin for 3 days. Flow cytometry was performed to detect the changes of T-lymphocyte subsets in PBMCs stimulated with Dsg3 and proliferation of T-lymphocytes. Results In patients with PV, the percentage of Th2 and Th1 cells was 12.17% ± 5.32% and 4.08% ± 1.50%, respectively in Dsg3-stimulated PBMCs, 9.84% ± 5.41% and 3.91% ± 1.38%, respectively in non-stimulated PBMCs. Increased percentage of Th2 cells was observed in Dsg3-stimulated and non-stimulated PBMCs from patients with PV compared with those from normal human controls （both P < 0.05）. After stimulation with Dsg3, there was a significant proliferation of T cells from patients, and the proliferation rate of CD4+ T cells was 4.65% ± 3.28%, which was significantly higher than that from normal controls （P < 0.05）. Conclusion Dsg3 can induce the specific proliferation of CD4+ T cells, especially Th2 type CD4+ T cells, from patients with PV.